public class SortList {
    /**
     * 给你链表的头结点 head ，请将其按 升序 排列并返回 排序后的链表 。
     * @param head
     * @return
     */
    public ListNode sortList(ListNode head) {
        if (head==null)
            return head;
        int length =0;
        ListNode node = head;
        while (node!=null){
            node= node.next;
            length++;
        }
        ListNode dumpyHead = new ListNode(0,head);
        for (int subLength =1;subLength<length;subLength<<=1){
            ListNode prev = dumpyHead,curr = dumpyHead.next;
            while (curr!=null){

            }
        }
        return null;

    }
}
